Prologue
The opening of the book mentions the case of a lady who had broken a number of habits: smoking, drinking, overeating, job-hopping, and being financially irresponsible. She had made dramatic changes to her habits in a four-year period.
This was one of "more than two dozen" who were subjects in a study of people who had made dramatic improvements in their lifestyle 'in relatively short periods of time."
Back to the original subject, she bottomed out - unemployed, divorced, and near to exhausting her credit limit, she came to the sudden relaxation that "everything I had ever wanted had crumbled" and she was looking for "at least one thing I could control."
The attempt to quit smoking was not done in isolation - she also took control of her diet, exercise, time management, and money management. She began setting positive goals (finish her education, run a marathon, buy a house) as well. Aside of the behavioral change, there were dramatic changes by her neural activity during this period.
Other subjects in the study showed a similar pattern: they began by focusing on changing one habit, called "the keystone habit," and applied that skill to change other routines in their life as well. It's briefly mentioned that organizations often follow the same pattern: one change, even a minor one, establishes a process for making others.
Consider that life is a mass of habits. A person's morning routine as they prepare for work, what they eat for breakfast, the route they drive, and so on are repeating behaviors. Most of our everyday decisions and not well-considered, but merely repeat the past. And we feel quite put-out when there is a disruption that requires us to deviate from these standard habitual behaviors.
He then considers the military. Basic training is about getting a group of people with highly idiosyncratic behaviors to completely change their life patterns and adopt a uniform set of habits. Everything that the recruit does is done at a specific time and in a specific way, from brushing his teeth to cleaning his rifle. There are standard procedures for battlefield tactics, establishing a base, and defending territory.
It is precisely for this reason that the military is so successful. The formation of common habits causes people to be able to perform under stressful situations, to collaborate with others they do not particularly like, and to accept and follow orders promptly, without argument.
The military also seeks to identify and alter patterns among the occupied population. It's noted that one insightful lieutenant put an end to riots by keeping food vendors out of plazas. This is because riots require a large crowd to form over a long period of time, and food vendors facilitated that. When there are no food vendors, the crowd disperses - or never forms - because people go home for lunch.
There's a brief mention of triggers - that a habitual behavior is initiated in response to some stimulus - but this is touched upon only briefly.
There's also the standard bit about the vast amount of research that has been done in recent years to help us better understand human behavior from both the psychological and neurological perspective, and a bit about the structure of the book.